These charts show why America's teachers are fired up and can't take any more

Updated 2241 GMT (0641 HKT) May 3, 2018

School teachers in the US today are being asked to do more with less, and many of them have had enough. The groundswell of unrest that began with a teachers' strike in West Virginia has spread to several other states. Frustrated teachers are staging walkouts, holding "walk-ins" and lining up to run for office.
How did things get this bad? Here are seven charts that help explain the problem.

Teaching is among the most respected professions in the US ...

Gallup asked Americans to rate 22 professions for their honesty and ethics. Grade school teachers came in third -- behind nurses, but far ahead of bankers, lawyers and politicians.

... and yet teachers' wages are lower than those of other college graduates

You can finish school, take pretty much any white-collar job -- accountant, human resources manager, whatever -- and earn more than a teacher.

For years, their salaries have remained flat ...

Salaries for US secondary school teachers have largely remained the same over the past two decades, according to the National Center for Education Statistics.

... and their pay is falling behind that of other workers

In 2010, teachers earned 12% less than workers in similar professions. By 2015, that gap had grown to 17%.